On Tue, Dec 8, 2009 at 1:44 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
_What_ flashes on/off? The screen (If so, it
sounds like a beam limiter
problem, the circuitry is detecting excessive CRT beam current and
cutting the CRT off to protect it). THe power-on LED (sounds like the
SMPSU Is tripping and restarting, maybe a short somewhere in the
horizontal output stage).
The display flashes on and off. It turns on and wiggles for a split second
like normal, lasts half a second, then goes out. Next second repeats. It's
a trinitron tube if that matters.
Does this monitor have a power-on LED? If so, what is it doing?
What are the CRT heaters doing? Do they go on and off too?
With something like this my first reaction would be to stick an analogue
votlmeter on some of the supply rails (they're often marked on the PCB [1],
anywy you might well get a service manual for a Sony monitor) and on the
CRT pins. See what, if any, supplies are pulsing on and off, see what CRT
pins are changing in voltage.
[1] I have a little Torch-badged Trinitron monitor on my XXX which has an
amazing amount of useful information marked on the PCBs. Voltages,
signals, CRT pinout, etc.
-tony